АТОМНО-АБСОРБЦІЙНЕ ВИЗНАЧЕННЯ ХРОМУ У КУХОННІЙ СОЛІ З ВИКОРИСТАННЯМ ЕКСТРАЦІЙНОГО ВІДДІЛЕННЯ МАТРИЦІ І ДІЇ УЛЬТРАЗВУКУ

The use of ultrasound in the determination of chromium in table salt using the extraction of the macrocomponent was investigated. The method of extractive separation of the base allows determination of the chromium content in table salt without destroying organic substances. Optimal conditions for dissolving the base in hydrogen peroxide (90 %) were experimentally established: temperature - from -20 to -25 °C, ultrasound frequency 18-44 kHz, intensity 0.5-0.8 W/cm², action time 20-25 s, respectively. At the same time, the maximum possible solubility of sodium chloride in hydrogen peroxide is achieved - up to 42 g/100 ml. It was established that the simultaneous use of high-frequency ultrasound (1.0-2.0 MHz, 0.25-0.50 W/cm²) and low-frequency ultrasound (18-100 kHz, 0.15-0.25 W/cm²) increases the solubility of sodium chloride in hydrogen peroxide from 42 to 47 g/100 ml, increase the degree of extraction of the injected part of chromium from 94-95 to 98-99 %. Methods for determining chromium content in common salt using low-frequency ultrasound, as well as simultaneous action of high- and low-frequency ultrasound with improved metrological characteristics of the results of analysis of common salt, have been developed. [ABSTRACT FROM AUTHOR]